1. Field of the Invention
The instant disclosure relates to an in-mold label and its producing method, more particularly to the in-mold label with a heat-sealable resin layer of a plurality of interlaced and continuous-arranged micro-protrusions.
2. Description of Related Art
Generally, if a picture or text needs to be printed on a bottle or surface of any article, a label with sticker is usually adapted to sticking the label with the article. In the process of sticking, some annoying blisters may stay inside the label if the blisters are not effectively driven out. Also, those inside blisters may cause the label easily to fall off.
Nevertheless, a kind of in-mold label has been developed in the conventional technology. In the process of producing a container or any product, one process selected from an injection molding, a blow molding, a differential pressure molding, and a foam molding is introduced therefor. In the process, a dry-type hot-melt adhesive is processed on the back side in advance. After a printing process, the glued label is fed and adhered to a specified position in a mold. The adhered label is with the forming plastics and formed in one piece in the mold. Further, the prepared dry-type hot-melt adhesive is adhered to the article or container. These described steps allow the thermoplastic label material with the printed picture or/and text to be embossed on the surface of any product. So that, the label is united with the product. For example, the kind of in-mold label is applicable to any surface of bottle for illustrating the product. Example of the in-mold label may not have problem of adhering the traditional label onto the product's surface since the label conventionally uses paper or the like materials.
Some conventional technologies are known to develop the methods to produce the in-mold label. The label may be usually made of paper or other like materials such as polypropylene or polystyrene. FIG. 1 shows a lateral view of an in-mold label disclosed in the specification of U.S. Pat. No. 6,551,671.
Example of the multi-layer structure of the in-mold label 10 is schematically shown in the figure. A substrate is a base layer 12 which is made of thermoplastic resin material. The upper surface of the structure is printed matter 13, which is the surface where the picture or text is printed thereon. The lower surface of base layer 12 is a heat-sealable resin layer 14. In one case, the surface 15 of the heat-sealable resin layer 14 has holes which are used for create the protrusions. Therefore, the blisters may be exhausted as fabricating the label and surface of product.
The mentioned heat-sealable resin layer 14 is formed as the heat-sealed layer on the product's surface, and the protrusions including top parts and bottom parts are useful to exhaust the blisters as fabrication. The related conventional technology can be referred to U.S. Pat. No. 5,254,302 which disclosed the surface structure of in-mold label as shown in FIG. 2.
The shown adhesive layer 20 is formed as a lattice pattern on the surface of a heat-sealable resin layer. The layer 20 includes the top part 22 and valley part 24. The top part 22 and the valley part 24 form the paths to exhaust the blisters when the layer is sealed on a surface. After that, the adhesive layer 20 may be completely sealed on the surface while the top part 22 and the valley part 24 disappear.